av_strerror(err, errbuf, sizeof(errbuf));
av_log(&file_log_ctx, AV_LOG_ERROR, "Error occurred in mmap(): %s\n", errbuf);
close(fd);
av_strerror(err, errbuf, sizeof(errbuf));
av_log(&file_log_ctx, AV_LOG_ERROR, "Error occurred in mmap(): %s\n", errbuf);
close(fd);